Activyl for Cats
This page contains information on Activyl® by Merck, flea prevention for cats.
What is Activyl?
Activyl is a monthly flea treatment that works by using a method called bioactivation, a method in which the active ingredient, indoxacarb is fully activated by using the flea’s own enzymes. Activyl can be used for both dogs and cats. It kills not only adult fleas but also flea eggs and larvae, which breaks the flea life cycle.
There are two dosage sizes:
- Small Cats (2 and 9 pounds)
- Large Cats (9+ lbs)
Active Ingredients
The active ingredient in Activyl is indoxacarb which is about 20% of the actual product.
How does it work?
The active ingredient of indoxacarb acts on the nervous system of the flea to cause paralysis and subsequent death. Within 8 hours of application on cats, 99% of fleas will have been killed.
The active ingredient in Activyl kills through contact, which means that fleas don’t have to bite your pet to die. Activyl is spread on your pet’s skin and coat. When a flea lands on your cat, it absorbs the active ingredient of Activyl and causes the enzymes start working. Activyl then reaches its full active form which causes the flea to become paralyzed and unable to feed. This process is called bioactivation.
How do you use Activyl?
Open the pouch and remove the tube. Hold the tube at the crimped end with the cap in an upright position (tip up). The cap should be rotated clockwise or counter clockwise one full turn. The cap is designed to stay on the tube for dosing and should not be removed. The tube is open and ready for application when a “click” is heard or felt. This indicates that the seal is broken and product can be applied to the cat.
The cat should be standing or lying with its back horizontal during application. Part the fur at the administration site. Place the tube tip vertically against the skin at the base of the skull of the cat.
Treatment at the base of the skull will minimize the opportunity for the cat to lick the product.
How to Properly Apply Activyl?
Part the hair on the neck at the base of the skull until the skin is visible. Place the tip of the tube on the skin and squeeze the tube to expel the entire contents directly on the skin. To make application easier, have your cat standing during application.
Warnings and Cautions
Do not get this product in your cat’s eyes, or allow your cat to ingest this product. The product is bitter tasting and salivation may occur for a short time if the cat licks the product immediately after treatment.
The safety of Activyl has not been established in breeding, pregnant and lactating cats. Use with caution in cats with a history of neurologic disorders.
Keep this and all drugs out of the reach of children. Do not contact or allow children to contact the application site until dry. Avoid contact with skin and eyes.
Activyl Indications & Contraindications
Use only on cats or kittens 8 weeks and older. Do not apply to cats or kittens weighing less than 2 lbs. Do not use on other animals.
● Do not apply more than one (1) tube per treatment, even for large cats.
● Do not have contact or allow children to have contact with treated area until completely dry.
● Do not use Activyl for dogs on your cat.
Effectiveness
Activyl for cats kills the existing fleas on cats within 8 hours with protection against further flea infestation lasting for up to four weeks. Preexisting pupae in the environment may continue to emerge for six weeks or longer depending upon the climatic conditions.
It is very important that all pets in the household are treated monthly – to prevent the flea life cycle from continuing.
Adverse Reactions
Side effects, although very rare, may include signs of skin irritation such as redness, scratching, or other signs of discomfort. Gastrointestinal signs such as hypersalivation, vomiting or diarrhea have also been reported.
Dosage & Safety Information
Activyl for cats should be administered topically as a single dose every 4 weeks.
Treatment with Activyl for cats may begin at any time of the year and can continue year round without interruption.
What happens if I miss a dose?
Give the dose when you remember and resume the normal application schedule of one application every 4 weeks.
Can it be used on kittens?
It is safe to use in kittens 2 months of age and older, and weighing 2.0 lbs or greater.
Can it be used on pregnant cats?
No, the safety of Activyl has not been established in breeding, pregnant and lactating cats.
Activyl Reviews
Activyl for Cats in the US Reviews
Activyl for cats reviews from owners in the US are similar, with nearly perfect ratings across the board on
One Activyl for cats reviewer on Amazon claims that it is works perfectly:
We tried using pills to kill the fleas. They would spit them out. A weekly bath routine with flea shampoo began. After months of alway finding a few fleas, I was at the end of my rope. Topicals before had not work for my longhair cats. After reading Merck’s literature it would break the flea cycle in one dose, I decided to try a topical one last time. I carefully opened the product before getting my cat. After the application, I decide the hold the cat an hour. It allowed the treatment to spread, dry and limit the licking of their fur. After one treatment, the fleas were gone.
However, some reviews from Amazon come with a caution, for example:
I’ve got sibling kitties – one of whom responds well to Activyl…. the other of whom lost all the hair on his neck the day after application! You could literally trace the line of application by his lack of hair!! Needless to say – we won’t be doing that again!
More Questions about Activyl…
How soon can I touch my cat after applying Activyl?
Let the application dry before touching your cat.
How long does it start to work after application?
Kills 100% of fleas within 8 hours of application.
Can my cat get wet/ how long does the cat need to stay dry?
While the product should be dry within 24 hours. Keep in mind that more frequent bathing may keep the product from working for the full 30 days.
My pet is on medication for another condition right now. Is it still safe to give Activyl?
Studies with Activyl have shown no interactions with routinely used veterinary medicinal products. However, it is always best to discuss all of your pet’s treatments with your veterinarian as they are your pet’s health care expert.
Does Activyl smell?
Labeling states there is no odor to this product.
Are there potential side effects of Activyl? What happens if my cat licks Activyl?
In cats, accidental ingestion may cause intermittent salivation, licking of the face, shaking of the head, and squinting.
How much does Activyl Cost?
Typically one round of dosage will cost between $25-$50 dollars depending of the size of your cat. Activyl cost will also depend on where the purchase is made, with purchases made from a veterinarian more expensive than is purchased online.
Where to Purchase Activyl?
Activyl is available from veterinarians and pet retail outlets, either in store or online.